<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
    <style>
      input[type="text"] {
        color: red;
      }

      [class~="wrapper"] {
        color: blue;
      }
    </style>
  </head>
  <body>
    <form action="http://www.baidu.com/s" id="first">
      <input />
      <input type="text" name="wd" />
      <input type="submit" value="百度一下" />
    </form>

    <div class="wrapper first odd">wrapper first odd</div>
    <div class="wrapper second even">wrapper second even</div>
    <div class="wrapper">wrapper</div>
  </body>
</html>
